1. Field of the Invention
Exemplary embodiments of the present general inventive concept relate to a fusing unit to fuse developer to paper and an image forming apparatus having the same.
2. Description of the Related Art
Generally, image forming apparatuses are devised to form an image on a printing medium, such as, e.g. paper, based on input image signals. Examples of image forming apparatuses may include printers, copiers, facsimiles, and so-called multi-functional devices that combine some of the functionalities of the aforementioned devices.
Such an image forming apparatus may include a printing media storage unit in which plural sheets of paper are received, a developing unit to feed developer to an electrostatic latent image so as to develop the electrostatic latent image into a visible image, an exposure unit to form the electrostatic latent image on a photoconductor of the developing unit, a fusing unit to fuse developer transferred to paper, and a paper discharge unit to discharge paper, on which the image is completely formed, to the outside of the body.
Given the above-described configuration, after light is irradiated to the charged photoconductor of the developing unit to form an electrostatic latent image on a surface of the photoconductor, developer may be fed to the electrostatic latent image formed on the photoconductor, to develop the electrostatic latent image into a visible image. Subsequently, the visible image formed on the photoconductor may be transferred to paper supplied from the printing media storage unit. As the paper passes through the fusing unit, the visible image transferred to the paper may be fused to the paper, completing formation of the image on the paper. The paper, on which the image is completely formed, may be discharged out of the body via the paper discharge unit.
Of the above-mentioned constituent elements of the image forming apparatus, the fusing unit may include a heating roller, and a pressure roller elastically supported on an outer peripheral surface of the heating roller, and a pair of paper discharge rollers to discharge paper, to which an image may completely be fused, out of the fusing unit. Thus, after developer is transferred and fused to paper passing between the heating roller and the pressure roller by heat and pressure transmitted from the heating roller and pressure roller, the paper may be discharged from the fusing unit via the pair of paper discharge rollers.
In the above-described image forming apparatus, when the paper passes between the heating roller and the pressure roller, the paper inevitably undergoes curling due to the heat and pressure transmitted thereto. Therefore, positions of the two paper discharge rollers of the fusing unit may be determined in consideration of paper curling. Since a curling degree will be changed according to various factors, such as the texture or moisture content of paper, etc., some paper may undergo serious curling beyond an appropriate level while passing between the heating roller and the pressure roller. This may make it impossible for the paper to enter between the paper discharge rollers of the fusing unit, thus causing paper jam.